The last time I was blown away by something I hadn't heard in rap was when Zev Love X reemerged as MF Doom. I think that was '95 or '96. Of course I'd never heard Killer Mike before RtJ though. I hated that stupid Outkast record on which he made his debut so if I did hear him it was under duress. I had a long stretch from like 2001 or 2002 til RtJ (2013) where I felt hip hop was so abysmal (even the underground!) that I just couldn't be bothered with anything but my precious old school favorites. Of which I have a million so it was easy to just dismiss everything without paying any real attention. This chick I know spammed RtJ on facebook so hard for so long that finally I had to listen. That was a happy day!
